I found a SID emulator library and I also found a webpage that haves thousands of Commodore 64 songs,how can I play these songs in arduino? I know that you just need to connect 1 or 3 speakers to the arduino,but is there IDE code that can play *.sid archives?

I think you would need a 6502 (6510?) emulator too - if I remember right, the C64 SID tune format is simply the 6502 machine code for the music playing subroutines extracted from the game it came from. A 6502 emulator would probably take too much memory though